Nuclear testing and the biota

It is said the "Bravo" blast was equal to 1,000 Hiroshimas. The Hiroshima bomb instantly killed 80,000 people. "Bravo" had the power to incinerate 80 million...

Marshall Islands endured 67 U.S. nuclear tests between 1946 and 1958, their net yield the equivalent of 1.7 Hiroshima bombs detonated every day for 12 years.

The impact that the nuclear radiation would have on the environment and people was not fully appreciated at the time the tests were conducted on Bikini and Enewetak Atolls. Many of the persons exposed to direct radiation, or consumed contaminated foodstuffs ended up with all sorts of health problems - primarily thyroid problems, including thyroid cancer, but also many other types of cancer such as leukemia, breast cancer and brain cancer. While at first it was felt that only a few atolls had received radiation, after studying the situation, Steven L. Simon, Director of the Nationwide Radiological Study and James C. Graham concluded that the only Marshalls' atolls which did not receive radiation from any of the tests were Namdrik, Lib, Jabot and Nadrikdrik. Other people contend, though, that even those received at least some radiation.

It is therefore easy to understand why many Marshallese would also think that the nuclear bombs have caused the decline in biodiversity that they have been observing since the tests were conducted in the 1940's and 1950's. At the biodiversity workshop on Namdrik, "poison from the atomic bombs" was statedly mentioned as a reason their bird population may be declining.

Not only in the Marshalls, however, but all around the world after the blasts, tales began to circulate of radiologically induced changes in the genetic makeup of certain species, even causing monstrous mutations. An extreme example is the science fiction story of Godzilla, which according to one version of the story at least, came about as an "abrupt mutation under the atomic bomb experiment held at off-shore Bikini Lagoon." (In other versions, this monster was aroused from wherever on account of such testing.)

Science fiction aside, serious tales are told which blame changes to the biota of the Marshalls on nuclear tests. Some mutations did seem to have occurred. Rats of Bikini and Enewetak were found with minor mutations, such as abnormal mouth ridges. These may be radiation related, but since this characteristic of the rats was not completely studied before the testing, it is not absolutely certain that this is actually on account of mutation or of a previously undocumented, naturally occurring genetic variation.

What happened to the traditional food crop, Polynesian arrowroot, "makmok" (Tacca leontopelaloides), is of more concern to the Marshallese than are rats with odd-looking roofs to their mouths. People repeatedly assert that after the bombs, the formerly healthy-looking plots of "makmok" became a rarity. Furthermore, even in the plants that appear healthy on the surface, what is actually found growing under the surface of the ground - the all-important edible tubers - are virtually nonexistent.

Unfortunately, no evidence could be found in researching this report that this concern has been addressed botanically. This would entail a "reciprocal transplant technique." "Makmok" plants from the Marshalls would need to be grown in soil from another area, and conversely, "makmok" from elsewhere would need to be planted in Marshalls' soil. Then the results could be compared and some sort of conclusion deduced.

Even if direct radiation is not the cause of the changes observed in "makmok," there may be other faetors related to the testing program that could have precipitated changes. Certain chemicals that were used to trace or "fingerprint" the tests. Many of these - arsenic, thorium, thallium and cadmium - are in themselves quite persistent and are easily absorbed by plants. Also, when radioactive material decays, it becomes lead. This element is similar assimilated by plants and could stunt their growth (it is also very harmful to people).

Not to be overlooked either is the possible introduction of some sort of pest, plant disease or other environmentally harmful factor at the time of the testing program.

The research done into the demise of "makmok" has concentrated on the effects of the changes in lifestyle, particularly the change from a rural society to an urban one. It is true that it takes a tremendous amount of effort to prepare "makmok," and nowadays more convenient starches are available to most people. However, "makmok" is not an intrinsically domestic plant totally dependant upon human cultivation in order to survive or thrive (in contrast to, for example, breadfruit).

The related problem of habitat disturbance and overexploitation could also be involved. Anthropologist Tom Dye, in a 1987 study of Arno, mentions that the introduction of pigs into an area was detrimental to "makmok" because these animals tend to tear up the roots of crops. None of these possibilities should be discounted without thorough investigation and experimentation.

Another less common contention similarly not yet addressed is that after the bomb testing, white spots appeared on the breadfruit in Majuro. However, no information was found of this change being specifically studied, nor of the possible introduction of breadfruit pests, at about the same time as the tests, being considered.

Ironically, when people had to evacuate the irradiated atolls, the plants, animals and their environments flourished. The participants from the Namdrik workshop had reason to be concerned about the declining population of birds. But from what has been observed on Bikini, Rongelap and other irradiated atolls, the birds are doing fine. This is not directly because of, nor in spite of the nuclear test program, but because the birds have had decades of being left alone with nobody to bother them.

"Clean-up" operations have been conducted for a few years on Bikini and have recently begun on Rongelap and may continue again soon on Enewetak. On Rongelap, the plans are to scrape off the rich, but "hot" soil from where the houses are to be built, and also use potassium fertilizer around the food crops.

It is a tedious, expensive process, and while it may make the island inhabitable again by people, it carries a lot of risks to the environment. A recent issue of the Marshall Islands Journal quoted one of the scientists involved in studying Enewetak's clean-up proposal as saying that soil-scraping would "substitute a radioactive disaster with an ecological disaster that would take 25-50 years to recover, if ever."

The natural resources - the fishes in the lagoon, the coconut crabs on shore, the birds - may seem abundant now. Yet how will they handle constant pressure from people, especially if they are harvested for food? Or if harassed by their pet dogs, cats, and pigs?

During the nuclear testing program, exotic plants were inadvertently brought into the land, and fouling marine species, such as hydroids, came into the lagoons on the ships. An early visit to the Rongelap clean-up project showed exotic plants, including weeds, around the old houses. These were probably remnants of when the people were living there. Will more exotic plants - even harmful invasive species - to be brought in? Furthermore, the heavy equipment and building supplies are perfect means of transporting invasive tramp ants. What would happen should some of these get established in the nesting grounds of the birds? Already, the long-legged ant is well established in urban Majuro. That species has been reported in the Seychelles to have invaded a colony of sooty terns (Sterna fuscata) and decimating 60,000 birds! That bird, called "oo" or "memij" in the Marshalls, nests on the ground in large numbers on the sandy islands ot the northern irradiated atolls. Could the same disaster occur there if the ant gets established?

The long-term aftereffects of radiation are still not entirely known, but it is felt that, given enough time - perhaps a very very ling time - the dangerous components will eventually dissipate and disappear on their own. Unfortunately, this is not the case with invasive plants and animals. Once they become established in an area, they often can not be eradicated. Biological, mechanica, and chemical controls sometimes may help, but often they do nothing, or worse, even amplify the harm.